De la macromolécule aux matières plastiques

Les matériaux polymères ont des propriétés rhéologiques extrêmement riches et diverses, à l'origine du champ très étendu de leurs applications industrielles et qui jouent un rôle essentiel dans leur mode d'obtention. Les différents comportements qu'ils présentent peuvent être expliqués par leur structure moléculaire et leurs propriétés dynamiques, si bien qu'ils constituent des modèles permettant d'expliquer par des mécanismes moléculaires relativement simples la grande variété des propriétés viscoélastiques des autres matériaux ..

Towards accurate stereo-video based free-surface reconstruction for wave tank experiments

Measuring accurately the shape of the free surface in medium-scale hydrodynamic testing facilities is challenging with conventional wave gauges. To overcome this problem, it is necessary to go towards higher resolution measurement systems. For this purpose, we investigate the ability of stereo-video acquisition systems to reconstruct free surface waves in laboratory conditions. This technique has been proven to give satisfactory results in open sea conditions, although it is dependent on the environmental conditions (weather, solar incidence angle). At sea, the stereo-video reconstruction algorithm makes profit of the short waves generated by the wind in order to correlate the points from the left and right images. The main challenge of adapting this technique to laboratory conditions, i.e. in absence of sun and wind, is to overcome the absence of texture on the free surface. This paper presents recent work aiming at developing a stereo-vision measurement system for laboratory conditions. Our efforts have been devoted to finding an adapted lighting system and generating a texture suitable for the reconstruction algorithm. Different lighting configurations have been tested in order to understand its impact on the reconstructions. For the texture generation, we have investigated different means of generating short surface waves (water droplets, air blowing, circulation current, underwater acoustic emissions) in different experimental facilities. Our conclusions show that it is possible to reconstruct the shape of surface gravity waves in the presence of short surface waves and that the effects of lighting and texture on the quality of the reconstruction are strongly coupled

A comprehensive review of genomic landscape, biomarkers and treatment sequencing in castration-resistant prostate cancer

International audienceHormone-naïve prostate cancer and its castration-resistant state (CRPC) are clinically and genetically heterogeneous diseases. From initiation of prostate carcinogenesis to its evolution towards therapeutic resistance, various combinations of genetic and epigenetic events occur. Schematically, progression to CRPC could be divided in two distinct pathways, either dependent or independent of the androgen receptor activity. Nevertheless, because the better knowledge of the genetic landscape of CRPC is under way, limited clinical applications are available at the moment, underlying the usefulness of prognostic and predictive biomarkers in daily practice. Despite the promising prognostic value of circulating tumor cells, no biomarker has been currently validated as a surrogate for overall survival in CRPC patients. Inversely, considerable interest has been generated with the recent finding of the splice variant AR-V7 that allows to predict resistance to abiraterone acetate and enzalutamide. However, other predictive biomarkers would be necessary to accurately guide personalized sequencing of CRPC treatment, which now includes numerous possibilities based on the six validated drugs, without accounting for those currently under investigation in the ongoing randomized controlled trials. As a consequence, only rational sequencing, which consists in choosing an agent that is not expected to have cross-resistance with previous therapy, can be currently advised

From bands to blobs: how final annealing changes super duplex stainless steel

International audienceSuper duplex stainless steel grades are modern stainless steel grades combining high specific mechanical properties with excellent corrosion resistance, especially to pitting corrosion. Their very specific microstructure consists in a mix of ferrite and austenite, usually at a 50/50 ratio, arranged in layers. This ratio is finely adjusted by a final annealing step during which, this fine, strongly banded microstructure evolves towards a coarser, globularized morphology in a matter of seconds. To determine the effect of annealing time and temperature on the final morphology, the kinetics of this morphological evolution have been quantitatively assessed in commercial and model alloys. In particular, stacks of austenite and ferrite with compositions found in the super duplex microstructure were assembled using HIP to produce an ideal super duplex microstructure with infinite, smooth bands. The obtained results suggest that grain boundaries and phase interfaces play a key role in the morphological changes. A phase field model of the polycrystalline two-phase microstructure was developed to simulate the observed phenomenon and rationalize the influence of the different parameters. Furthermore, the change in morphology of the phases was quantitatively analyzed against the change in mechanical properties. TEM and EBSD observations allow to relate these variations to the arrangement of dislocations in the microstructure. The present study affords a better understanding of the effect of final annealing on the microstructure of super duplex and opens new possibilities to tailor their properties

BlueBrain/Brayns: 3.4.0 Release

Visualizer for large-scale and interactive ray-tracing of neuron

BlueBrain/Brayns: 3.2.2 Release

Visualizer for large-scale and interactive ray-tracing of neuron

BlueBrain/Brayns: 3.3.0 Release

Visualizer for large-scale and interactive ray-tracing of neuron

BlueBrain/Brayns: 3.5.0 Release

Visualizer for large-scale and interactive ray-tracing of neuron

BlueBrain/Brayns: 3.5.1 Release

Visualizer for large-scale and interactive ray-tracing of neuron